The present invention relates to non-interference stress measurement systems (NSMSs) for use with gas turbine engines.
Non-interference stress measurement systems (NSMSs) are known for collecting structural data about gas turbine engine components (e.g., using blade vibration measurements correlated to blade stress) that is used, in turn, for engine design purposes and for engine certification processes. Typically, these NSMSs have been configured for test stand applications. In other words, these NSMSs have been configured to gather data from prototype or other non-airframe-mounted gas turbine engines in a test facility. These systems utilize sensors to measure stress in engine components, and relay those signals to ground-based electronics that process the data. Generally, these known NSMSs have utilized large component cabinets located on the ground and linked to sensors on a test engine through fiber optic cable. An operator on the ground must calibrate and coordinate operation of these NSMSs. For instance, operators can manually set a hold-off period for sensed vibration data that remains fixed for a given test procedure, absent any further manual adjustments made by the operator to that fixed period. Operator involvement can decrease the accuracy and repeatability of NSMS measurements due to human error.
In some circumstances it is desirable or necessary to collect in-flight engine structural data while an engine is mounted to an airframe. However, known NSMSs generally cannot function in such in-flight situations. Furthermore, known systems are large and heavy, and cannot be readily mounted to an airframe for in-flight operation, and require a human operator.